A blood vessel can be any vascular structure, e.g., an artery, a vein, or a capillary. A dilated blood vessel is usually associated with any one or more of a variety of disease conditions, e.g., telangiectasias and varicose veins.
Telangiectasias are skin manifestations of primary cutaneous disorders and systemic diseases. For example, linear telangiectasias are seen on the faces of patients with actinically damaged skin and acne rosacea and are found on the legs of patients with venous hypertension and essential telangiectasia. Mat telangiectasias are lesions of broad macules and are commonly found on the face, oral mucosa, and hands of patients.
Cutaneous disorders associated with telangiectasias include acne rosacea, actinically damaged skin, venous hypertension, essential telangiectasia, ionizing radiation, and Poikiloderma vasculare atrophicans. Telangiectasias are also associated with systemic diseases such as carcinoid, ataxia-telangiectasia, mastocytosis, dermatomyositis, xeroderma pigmentosa, scleroderma, lupus erythematosus, hereditary hemorrhagic telangiectasia, and cirrhosis.
Varicose veins are dilated, tortuous superficial veins that result from defective structure and function of the valves of the veins, from intrinsic weakness of the vein wall, or rarely from arteriovenous fistulas. Varicose veins can be categorized as primary or secondary. Primary varicose veins originate in the superficial system while secondary varicose veins result from deep venous insufficiency and incompetent perforating veins, or from deep venous occlusions causing enlargement of superficial veins that serve as collateral veins.
Patients with varicose veins are often concerned about the cosmetic appearance of their legs, but varicose veins are also often associated with various physical symptoms as well. For example, symptoms can include a dull ache or pressure sensation in the legs after prolonged standing. In addition, extensive venous varicosities may cause skin ulcerations near the ankles. Superficial venous thrombosis may be a recurring problem and rarely a varicosity ruptures and bleeds, leading to more severe symptoms.
Treatments for dilated blood vessels, especially varicose veins, include sclerotherapy and surgical therapy. In sclerotherapy, a sclerosing solution such as hypertonic saline or surfactants is injected into the involved blood vessels, which results in deformation of the vascular structure. Surgical therapy involves extensive ligation and stripping of the greater and lesser saphenous veins. However, administration of these therapies usually requires high technical skill. Furthermore, the common patients, fear of needles and surgical procedures prevents many from seeking these treatments.
Laser and other light sources have also been used in photothermolysis therapy to treat dilated blood vessels, such as varicose veins. Selectively-absorbed light, e.g., in the form of pulses, is used to damage the vessels while sparing the surrounding tissues. However, reperfusion of treated blood vessels reduces the effectiveness of the treatment. Multiple treatments are often required because of reperfusion of a treated vessel. In addition, reperfusion of a treated vessel is undesirable because of clotting factors and thrombolytic factors associated with the process. Photothermolysis therapy is in common use for lack of a better alternative despite the relatively high cost, number of treatments, and risk of post-treatment pigmentation.